Also, you can set up the qubes to run the the GPU easily enough, and you can have all your guests do it at the same time.
VirtualGL I think it was called. At least from what I know that is what it does. I’ll find the post… here you go…
https://forum.qubes-os.org/t/seamless-gpu-passthrough-on-qubes-os-with-virtualgl/
You can have a look and decide, you may understand it better than I did.
The GPU rendering doesn’t affect CPU that much. Al my guests barely even touch the CPU with video rendering or anything like that if they are using the seamless mode for the Qubes Drivers.
Once the compositor is reset it really doesn’t lag much ever at all. If the guest runs low on RAM, then everything lags in that guest though.